Spindle bearing construction



Oct. 17, 1950 I s. E. SCHROEDER 2,526,049

SPINDLE BEARING CONSTRUCTION Filed May 12, 1944 12433 edefl wf w MW/7%0r/z s.

Patented Oct. 17, 1950 SPINDLE BEARING CONSTRUCTION Simon E. Schroeder,Ripon, Wis., assignor to Speed Queen Corporation, a corporationv ofDelaware ApplicationMay 12, 1944, Serial No. 535,338

6 Claims.

1 The invention relates generally to bearings and more particularly to abearing construction for a high speed spindle of a machine tool or thelike.

' The general object of the invention is to provide a novel spindlebearing construction capable of maintaining a high degree of trueness inthe operation of the. spindle.

Another object is to provide a novel spindle bearing arrangement so thata predetermined clearance between the spindle and the bearing will beattained.

Other objects and advantages will become apparent from the followingdescription, taken in connection with the accompanying drawing, inwhich:

Figure 1 is a vertical sectional view of a spindle bearing constructionembodying the features of the invention.

Figv 2 is a diagrammatic view illustrating the .method of assembling thespindle within the bearing structure.

While the invention is susceptible of various modifications andalternative constructions, I

have shown in the drawings and will herein describe .in detail, thepreferred embodiment, but it is to be understood that I do not therebyintend to limit the invention. to the specific form d sclosed, butintend to cover all modifications and alternative constructions fallingwithin the spirit and scope of the invention as expressed in theappended claims. 7 In machine tools. the accuracy of the work iperformed thereby is dependent upon the accuracv of'operaton of thespindle carrying either. the tool or the work as the case may be. It istherefore the constant aim of machine tool designers, as well asdesigners of kindred products, to provide a bearing construction forsuch spindles, particularly those operating at relatively high speeds,which accurately mainta ns the spindle in the desired position duringoperation of my invention.

The embodiment shown in the drawing comprises a supportor head Illcarrying a spindle I l on one end of which may be mounted a grind ingwheel [2. The head or support It! is adapted to be. mounted upon a baseor frame (not shown) of a machine. The spindle II is located in alongitudinal bore [3 extending through the supacter as to providelubrication over substant ally the entire area of the bearing surfaces.With such complete lubrication, the clearance between the bearingsurfaces of the spindle and the bearing structure may be reduced to aminimum without danger of overheat ng the parts during op ration; Tothis end the invention contemplates the use o a bearing member made ofporous metal, and the provision of means to supply oil to the bearingmember under pressure so thatthe porosity of the bearing member per--mits the o l to be forced therethrough to substantially the entire areaof the bearing surface. Thus the bearing surface supporting the spindleis subject d to substantia ly complete lubrication notdependent upon theclearance between the spindle and the bearing member. Such clearancemay. therefore be held to a minimum without "interfering with properlubrication, and a hi h degr e of truene s in the rotation of the spindlis thereby obtained.

In the pref rred embodiment shown in the drawings, a pair of axiallvspaced annular bearing members [5 are provided. These are made of porousmetal such as sintered bronze or metal known in the trade as OiliteBearing Bronze, thebearing members [5 having a'press fit within' thebore is of the head, and the interior annular surfaces of the bearingmembers supporting'the spindle ll.

To lubricate the bearing members, the head I!) is provided with a pairof annular grooves l6 opening into the bore l3. The grooves l6 a'r'e'located intermediate the ends of the re-' 151m. communication witharadial passage l1, and the latter are connected to a source of oilunderpressure' (not shown) by means of piping 18. Thus oil underpressure is supplied to each groove I 9 and because of the porosity ofthe bearing member, the oil permeates the entire body thereof and isforced therethrough to the bearing surface throughout substantially itsentire area.

Excess oil working out from the ends of each bearing member is collectedand returned to the source of supply. To this end a central well 20 isprovided in the head 10 between the two bearing members so that oilworking through to the inner ends of the bearing members is collected inthe well and carried back to the source of supply through a pipe 2|. Atthe outer ends of the bearing members are annular wells 22 closed bysealin rings 23. The wells 22 communicate at their lower end with drainpassages 24 slanting downwardly toward and opening into the central well28. Thus excess of oil forced through the bearing members [5 isconducted back to the source of supply.

Although the grinding wheel I2 is utilized for peripheral grinding andthe bearing construction consequently is designed primarily for radialload, the spindle H must be held against endwise movement. In thisrespect the bearing members i 5 which have a press fit within the headii! are utilized to hold the spindle against endwise movement. To thisend a pair of thrust rings 25 are mounted within the bore I3 in abutmentwith the inner ends of the respective bearing members I5, and betweenthe thrust rings is an adjustable collar means adapted to be rigidlysecured to the spindle and abutting endwise against the two thrust rings25. To provide space for the adjustable collar means, the central well20 is sufficiently enlarged.

In the preferred form, the adjustable collar means comprises a rin 26fitting snugly on the spindle and adapted to be rigidly secured theretoas by set screws 21. The ring 26 abuts endwise against one of the thrustrings 25 and is threaded as at 30 to receive a flange 3| on a collar 32likewise snugly fitting the spindle. The collar 32 abuts endwise againstthe other thrust ring 25. flange 3! on the ring 26 the collar means isheld in endwise abutment with the two thrust rings 25, and since thering 26 is secured to the spindle, the latter is held against endwisemovement relative to the bearin members l5. flange 3! is adapted to berigidly secured to the ring 26 when in adjusted position by means of aset screw 30'. The ring 26 and collar 32 are adapted to be placed inposition within the head In by extending the well 20 upwardly to openthrough the top of the head 50. When the parts are properly adjusted,such upper opening of the well 20 is closed by means of a removablecover plate 33.

As mentioned above, lubrication of the bearing surfaces is not dependentupon the amount of clearance between the spindle and the bearing membersl5. For this reason such clearance may be of a predetermined size. Toobtain such clearance the internal bearing surfaces of the members [5and the external surface of the spindle are ground to a slight taper, asindicated in Fig. 2. In assembling the structure, the spindle isinserted endwise into the bearing members and forced therein until thetaper causes the bearing surfaces to fit tightly. Such position is shownby the full lines in Fig. 2. When the spindle is in such position thereis substantially no clearance between the spindle and bearing members.The spindle is then Thus by properly adjusting the The moved back apredetermined distance which, because of the known angle of taper,provides a predetermined clearance between the spindle and bearingmembers. Such position is shown in dotted lines in Fig. 2. The spindleis then looked against endwise movement by means of the ring 26 andcollar 32 so that the clearance will thereby be maintained.

As an example of the amount of clearance obtained in this manner for agrinding Wheel spindle, such as is illustrated in the drawings, thetaper of the coacting bearing surfaces of the bearing members andspindle may be .0005 of an inch. The spindle is preferably moved backfrom its tight fitting position one-half of an inch, which results in aclearance on each side of the spindle of .00025 of an inch.

The complete lubrication of the bearing surfaces effected by forcing theoil through the porous bearing members l5 will prevent to a great extentany overheating during operation. However, it is desirable to be surethat the spindle is maintained at a fairly constant temperature so thatthere will be no inaccuracy of grinding resulting therefrom. To this endthe spindle is water cooled by a constantly flowing stream of waterentering an internal bore in the spindle. As shown herein, the bore,indicated at 34, opens outwardly through the end of the spindle oppositeto that carrying the grinding wheel. Threaded into the open endof thebore is a plug 35. The latter is likewise provided with a bore which atits outer end, indicated at 35, is of such size as to fit snugly arounda pipe 3?. The pipe 31 is connected to a water supply (net shown).Within the bore 24 the pipe extends substantially to the inner endthereof, being spaced a slight distance from suchinner end to permitpassage of the Water from the pipe into the bore 3d. To carry the wateraway from the interior of the spindle, the bore in the plug 35 isenlarged as at 40 to communicate with radial passages ii through theplug to an annular groove 62 in a collecting ring 43. The collectingring 33 is mounted externally on the plug 35 and is held againstrotation with the plug. The annular groove "52 communicates with a drainpipe is threaded radially into the collecting ring d3. Thus waterflowing through the pipe 3'! cools the interior of the spindle duringits passage through the bore 34 and is drained off through the pipe 54.The water thus carries away any heat that might be generated duringoperation of the spindle.

From the foregoing, it will be apparent that I have provided a spindlebearing construction in which the entire area of the bearing surfaces onthe spindle and bearing members is lubricated in a novel manner. Theporosity of the metal permits the oil under pressure to permeatethroughout the bearing members and thus lubricate substantially theentire bearing surface thereof. Such lubrication is not dependent uponthe amount of clearance between the spindle and the bearing members sothat such clearance may be held to a predetermined minimum. To set thespindle for such minimum clearance the taper grinding of the bearingsurfaces permits the spindleto be shifted to a position relative to thebearing members that will provide the desired clearance. The spindlewhen so shifted is held against endwise movement relative to the bearingmembers so that the clearance is maintained throughout operation.Lubrication in this manner substantially prevents overheating of thespindle and the spindle itself is water cooled so that excess heat,should any arise, will be carried away.

I claim as my invention:

1.,A spindle bearing construction comprising,

in combination, a support having a longitudinal bore extendingtherethrough, a pair of axially spaced annular bearing members mountedin said bore, a spindle mounted in said bearing members, said bore beingenlarged intermediate positioned a predetermined distance from theposition where it fits'tightly within said bearing members to provide apredetermined clearance between the bearing surfaces, said collarmeansbeing locked to saidspindle to hold it against axial movement relativeto the bearing members.

2. A spindle bearing construction comprising,

* in combination, a support having a longitudinal bore extendingtherethrough, a pair of axially spaced annular bearing members mountedin said bore, a spindle mounted in said bearing members, said bore beingenlarged intermediate said bearing members, and an axially'shiftable andaxially extensible and contractible collar adjustably securedto saidspindle within said enlarged portion of said bore and bearing endwiseagainst said, 1

bearing membersgsaid bearing members and said spindle having slightlytapered coacting bearing surfaces, said spindle being longitudinallypositioned by saidcollar a predetermineddistance from the position whereit fits tightly Within said bearing members to provide a predeterminedclearance between the bearing surfaces.

said support being provided with two opposed shoulders spaced axially ofsaid spindle, and an axially extensible and contractible adjustingcollar secured to said spindle betweensaid shoulders, said collarincluding a first ring slidable on said spindle and adapted to berigidly secured thereto in different positions of axial adjustment andfor maintain a predetermined clearance between said bearing surfaces.

5. -A spindle bearing construction comprising, in combination, anannular bearing member having an internal bearing surface with a slightpredetermined taper, a spindle having an external bearing surface with ataper complemental to said first-mentioned taper and adapted to beinserted axially in one direction into said bearing member to a pointwhere said spindle fits tightly with said bearing member, and an axiallyextensible and contractible collar slidably adjustable on said spindleand adapted to coact endwise with said bearing member to constrain saidspindle against endwise movement in an axial position of adjustment soas to afford a predetermined clearance between said surfaces.

' 6. A spindle bearing construction comprising, in combination, abearing support, a pair of axially spacedannular bearing members mountedin said support, means in said'support defining two opposed shouldersspaced axially of said 3. A spindle :bearing construction comprising,

in combination, a support having a longitudinalbore extendingtherethrough and enlarged intermediate its ends, a pair ofaxially-spaced annular bearing members mounted in the opposite endportions of said bore, a spindle mounted in said bearing members,adjustable means on said spindle within the said enlarged portion ofsaid bore and coacting with said support to locate said spindleadjustably in different relative axial positions and to constrain saidspindle against endwise movement in any selected position of adjustment,said bearing members and said spindle having slightly tapered. coactingbearing surfaces,

said bore, a spindle extending through said bearing member, said spindleand bearing member having slightly tapered coacting bearing surfaces,

' bearing. members, a spindle extending through and 'journalled in saidbearing members, anaxially extensible and "contractible adjusting collar1 secured to, said spindle 'between'said shoulders,

REFERENCES CITED The following references are of record in the file ofthis patent:

V UNITED STATES PATENTS Number Name Date 1,257,773 Wiberg Feb. 26, 19181,437,560 Shearer Dec. 5, 1922 1,550,834 Miller Aug. 25, 1925 1,873,146Patch Aug. 23, 1932 2,080,750 Thompson May 18, 1937 2,319,740 Lapsley lMay 18, 1943 2,266,968 Hamilton Dec. 23, 1941 Certificate of CorrectionPatent No. 2,526,049 October 17, 1950 SIMON E. SCHROEDER It is herebycertified that error appears in the printed specification of the abovenumbered patent requiring correction as follows:

Column 6, line 63, list of references cited, after Dec. 23, 1941 insertthe following:

OTHER REFERENCES Product Engg, Oct. 1932, page 407. Published by McGmw HM Publishing 00.

and that the said Letters Patent should be read as corrected above, sothat the same may conform to the record of the case in the PatentOfiice.

Signed and sealed this 26th day of December, A. D. 1950.

[sun] THOMAS F. MURPHY,

Assistant Commissioner of Patents.

